If it thumps each time you accelerate and again when you decelerate or when it shifts, it could be broken motor mount(s). I agree with the motor mounts OR do you mean the thumping you hear/feel when you have a tire that is out of round, broken tire belting or the wheel weight has fallen off? If this is the case take your Jeep to a tire center and have them drive the jeep to check out what they say.
The loud whining sound could be wheel bearings going out. However, it is also possible that the speedometer bearings or cable are defective.
A CV joint in one of the front halfshaft axles is going bad.
Signs of a worn timing chain are difficulty starting in cold weather with backfire and sudden brief loss of power while accelerating or decelerating ("stumbling").
No, the Grand is different from the Cherokee.
The Grand Cherokee did not exist until the 1993 model year.
A seat from a 1999-2004 Grand Cherokee is what fits in a 1999-2004 Grand Cherokee.
None, there wasn't a Grand Cherokee until 1993None, there wasn't a Grand Cherokee until 1993
no.
Jeep Grand Cherokee was created in 1993.
It most likely will, grand Cherokees didn't change much those years. As long as they are both grand Cherokees, and as long as one isn't a Cherokee and the other is a grand Cherokee.
No, the XJ Cherokee does not have the same heater box as a WJ Grand Cherokee.
The grand Cherokee is a body style, sport is a trim package that is used on all jeep models(wrangler, Cherokee, grand Cherokee, patriot, ...)